Minimizing Group Index Variations in a Multicore Endoscope Fiber

Ultrathin endoscopes based on multicore fibers and adaptive optics: a status review and perspectives

“…So even though the MCF reported in Ref. 50 permitted coherent combination of 100 fs pulses after 2 m of MCF, the MCFs in Figs. 2(a) and 2(b) can in principle be brought to the same level of performance with a suitable group delay compensation scheme which we will discuss in Sec.…”

Multi-Core Optical Fibers: Theory, Applications and Opportunities

“…Later, in 2013, Andresen and co-workers realized a lensless endoscope employing a MCF similar to Figure 11(a) with extremely low IC-XT between adjacent cores [113]. In the same line, additional works have been reported combining MCF and MM-SCFs with adaptive optics in [114][115][116][117][118][119][120]. At present, the major aim in lensless endoscopy using MCF media is to increase the core density with a reduced IC-XT and intermodal dispersion between neighboring cores [121].…”

“…Multi-core optical fibers have also been studied in recent years within the context of medicine for biomedical sensing and imaging applications [112][113][114][115][116][117][118][119][120][121]. Basically, biomedical sensors using MCFs are based on the MMI technique previously described.…”

“…The waveguide should be capable of acquiring a multiphoton image of an object located at its tip. To this end, MCFs have been proposed as a necessary technology for the realization of ultrathin lensless endoscopes [112][113][114][115][116][117][118][119][120][121]. Figure 11 depicts different MCF types proposed for biomedical imaging along with a basic scheme of adaptive optics using a spatial light modulator (SLM).…”

Single-shot polarimetry imaging of multicore fiber

“…At the exit of the bundle, the different beamlets are recombined in a single beam and their relative phases are adjusted by a servo for coherent synthesis of an amplified ultrashort pulse or a focused spot, depending the application. Optimal temporal and/or spatial, focus at the bundle output requires to actively manage the relative beamlet phase and group delay [13,14] together with their polarization state. Recent works report the use of polarization-maintaining (PM) MCF [9,15] to ensure that the output beamlets exhibit identical polarization states for optimal spectral and/or spatial interference.…”